Commercial golf balls today consist generally of three types of configurations. The first type is a multi-piece, wound ball in which a vulcanized rubber thread is wound under tension around a solid or semi-solid core, and thereafter enclosed in a single or multi-layer covering of a tough, protective material. A second type of a golf ball is a one-piece ball formed from a solid mass of resilient material which has been cured to develop the necessary degree of hardness to provide utility. A third type of ball is a multi-piece, non-wound ball that includes a liquid, gel or solid core of one or more layers and a cover having one or more layers formed over the core.
Conventional golf ball covers have been made of ionomer, balata, and slow-reacting, thermoset polyurethane materials. When polyurethane covers are made by conventional methods, such as by casting, a substantial amount of time and energy is required, thus resulting in relatively high cost. In addition, when producing one or more core and/or cover layers from polyurethane, other processing problems occur, including discoloration due to ultra-violet light, slower reaction times, and insufficient physical properties. Although satisfactory in some respects, a need exists for improved polyurethane formulations and methods of producing golf balls and components thereof.
It would be useful to develop a golf ball containing a fast-chemical-reaction-produced component, such as at least one core or cover layer, particularly one which contains polyurethane, polyurea, epoxy and/or unsaturated polyester.
It would also be useful to form a golf ball core, interior, or cover layer from a reaction injection molding system using a suitable cross-linker that provides little or no discoloration due to ultra-violet light, has fast reaction times, and exhibits good physical properties.
It would be particularly desirable to provide a multi-piece golf ball of the third type previously described utilizing the noted fast-chemical-reaction-produced component and/or the noted cross-linker.
Another object of the invention is to provide a method of making a golf ball of the type described above.